diff --git a/tests/hazmat/primitives/test_ec.py b/tests/hazmat/primitives/test_ec.py
index f61b4a9..53985fe 100644
--- a/tests/hazmat/primitives/test_ec.py
+++ b/tests/hazmat/primitives/test_ec.py
@@ -71,3 +71,9 @@
                     2, 3, None
                 )
             )
+
+        with pytest.raises(TypeError):
+            ec.EllipticCurvePrivateNumbers(
+                1,
+                None
+            )